1. Technical Field
The present invention relates to a lens array substrate, an optoelectronic device, and an electronic apparatus.
2. Related Art
There is known an optoelectronic device that is provided with an optoelectronic material such as a liquid crystal between an element substrate and an opposite substrate. Examples of an optoelectronic device include a liquid crystal device used as a liquid crystal light valve of a projector and an imaging device used as an imaging unit of a video camera. In a liquid device, a light-blocking portion is disposed in an area where a switching element, wiring, and the like are arranged, and a part of incident light is blocked by the light-blocking portion and is not used. From this point, there is known a configuration that is intended to improve the efficiency of use of light in the liquid crystal device by providing a microlens in at least one of the substrates, condensing light that is a part of light being incident on the liquid crystal device and is blocked by the light-blocking portion arranged at the boundary between pixels, and allowing condensed light to be incident into an opening portion of a pixel (for example, refer to JP-A-2014-089230).
The microlens with which the liquid crystal device disclosed in JP-A-2014-089230 is provided includes a first lens and a second lens. The first lens is on the incidence side of the liquid crystal device and is configured by filling a concave portion formed in the substrate with an inorganic material having a higher refractive index than the substrate. The second lens is formed into a convex shape on the first lens with an inorganic layer (optical path length adjusting layer) interposed therebetween. The cross-sectional shape of the first lens and the second lens is substantially hemispheric. The planar shape of the first lens and the second lens is rectangular or substantially circular. Neighboring lenses may be formed independently.
Incidentally, in the liquid crystal device provided with the two-stage microlens as disclosed in JPA-2014-089230, when, for example, neighboring first lenses are formed independently, between the neighboring first lenses is a flat surface that is substantially parallel to the upper surface of the substrate. When neighboring second lenses are connected to each other, light that is incident on the flat surface between the neighboring first lenses travels without being refracted in the first lens and is incident on an end portion of the second lens. The angle between the upper surface of the substrate and the curved surface of the lens is large in the end portion of the second lens of which the cross-sectional shape is substantially hemispheric. Thus, when light is incident on the upper surface of the substrate to the end portion of the second lens in a substantially vertical direction, the light is totally reflected in the second lens to travel in an inclined direction or is scattered, thus causing stray light. When such stray light occurs, this may cause the contrast of the liquid crystal device to be degraded or cause degradation of display quality such as flickering and crosstalk due to an increase in an optical leakage current in a TFT. In addition, even in a case where the imaging device is provided with the two-stage microlens, when stray light occurs as described above, this may cause the S/N ratio and the resolution of gradations in a captured image to be degraded.